Straight-edge



M. K. VON ZIMMERMANN STRAIGHT EDGE Filed March 24, 1954 Patented June 25, 1935 "UNITED STATE s PATENT oFFlcE STRAIGHT-EDGE Maxv Kurtvon Zimmermann,y Elkhart, Ind.

Application March 24,

tion with respect to said board. Other objectsr and advantages of this invention will appear from the following specification and the drawing in which- Figure 1 is a top plan view of one type of board embodying my invention; Fig. 2 is a side view along the line 2 2 of Fig. l; Fig. 3 is a fragmentary side sectional view along the line 3--3 on Fig. 1, showing the straight-edge and its supporting means when said straight-edge is in a lowered position; Fig. 4 is a View similar to that of Fig. 3, but showing the straight-edge in a raised position; Fig. 5 is a sectional View along the line 5 5 of Fig. il, showing the locking means in more detail; and Fig. 6 is a vertical sectional view along the line 6-6 of Fig. 4.

In the illustrations the drawing or writing board is indicated by the reference numeral I0. This board has in connection therewith straight edges II and I2, preferably of metal. These straight-edges are parallel -to their adjacent edges of the board IIJ and are perpendicular to each other. lar function and are similarly mounted in the board so that we shall consider only the mounting of one of them, that of the straight-edge I2. The straight-edge l2 lies in a recess or groove I3 in the board I0, this groove having sufficient depth that the straight-edge may sink into it until its upper surface is flush with or below the level of the surface of the board II). Near the ends of this groove, the board has holes I4 bored therethrough which holes contain metal inserts I5 which have a driving t therein. -These metal inserts are also slotted or grooved so that the straight-edge I2 recesses therein. Sloping slots I6 in the straight-edge I2 engage pins or members Il in the metal inserts I5,'which members are positioned transversely with respect to the straight-edge and form supports therefor. Y

The straight-edge I2 has near the center thereof notches I8 and I9 adapted to cooperate Witha yieldingly Both straight-edges perform a simi-v 1934, serial No'.=717,246; 5 claims. (c1. .2e-76p' Y 20. metal, spring is carriedin a. metal plug 2| which has adrivi'ng'fitin-ahole 22 through said board 1I'0. The metalplug- 2I has ynear its base a pin 23 forming a supporting means about ocking means,v as a metal spring which the spring 20 is coiled in order to retain it in its proper relation with the plug 2| and the c'.

straight-edge I2.

In this form of my device the straight-edge is raised or lowered by applying a manual force tending to move it longitudinally. The longitudinal movement acts through the slope of the slots I6 to change the vertical level of saidstraight-edge.- The straight-edge is held in the raised or lowered position by the yielding engagement of the spring 20 with one of the notches I8 and I9. It is understood, of course, that other notches may be employed if it is desired to lock the straight-edge at any intermediate position.

This form of support for the straight-edge is very effective in that it does not permit the straight-edge to become separated from the board. The straight-edge is at all times immediately available for use with a triangle or other drafting aid, yet it may be lowered to its recessed r position and present no obstacle to the use of other straight-edge devices as T-squares or the y like. The notch and spring locking Ameans in combination with the sloping slots provide a supporting means for the straight-edge which holds it in a desired position irrespective of the vertical pressures which may be applied toit in the ordinary course of drafting, yet a relatively easy manual longitudinal pressure serves n Changes, therefore, in the construction and arrangement may be made without departing from the Spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in"my.in vention as broadly as possible in view of the prior art.

What I regard as new, and desire to secure by Letters Patent, is: n

1. A board of the character described, having in` combination: a groove in said board; a straight-edge adapted to lie in said groove;` diagonally sloping slots in said straight edge; and members on said board adapted to be engaged by said slots, whereby longitudinal movement of said straight-edge effects a change in the vertical level thereof.

-2. A board of the character described, having in combination: a groove in said board; a straight-edge adapted to lie in said groove at a plurality of different levels, at least one level being flush with or below the surface of said board; diagonally sloping slots in said straightg edge; members on said board adapted to be enkstraight-edge adapted to lie in said groovefaba plurality of different levelst leastnonelevel. being flush with or below the level of said board; a diagonally sloping SIOtJIisaidJStraigM--edgeLz an insert in said board-having a. pinstherein` e adapted to be engaged by said slot, whereby Iongitudinslffmovemen-tlof: straight-meg clients a. fchange. im the; yertical: levelathereo! p1 a. notch inl .saich straight-edge 5 :and t'meamszaadapted to yieldingly. 1; engages .1 said `rlnotnh', wherebyz: said level.

straight-edge may be locked at a desired vertical.

4. A board of thek character described, hay;

ing in combination: a groove in said board; a straight-edge adapted to lie in said grooveat a plurality of diierent vertical levels, at least one Y level being ush with or below the surface of said board; a notch in said straight-edge; and meansk adapted to yieldingly engage said notch, wherebysaidstraight-edge may be locked. at a desired vertical level. l

5. A board `of the character described, havin combination: agroove in said board; a straight-edge adapted to lie in said groove at a plurality of dierent vertical levels, at leastone 1eve1- 1061118I ,flushwith or below the surface of said board; a metal plug in said board adiacent t0I saidlstraight-edgmsa yielding spring projecting Afrom said plug; and a notch in said straightedge ladapted to be engaged by said spring, 20

whereby Lisaid-straight-edge may gbeyflockedzfata desired; vertical level; Y.

MAXKUR'I, `VON,V ZIMMERMANN 

